SEOUL (Reuters) - The parent of top South Korean gaming firm Nexon Co Ltd has delayed the bidding process scheduled this week for its controlling stake in the company, two sources familiar with the matter told Reuters, sending its shares sharply lower.

Any postponement will raise concerns for the future of a deal that would rank as one of South Korea’s biggest, and at potentially $16 billion, the biggest gaming deal worldwide.

“How the deal is going forward is uncertain, that is hitting shares of Nexon companies that are responding a lot to news related to the sale,” said Lee Chang-young, an analyst at Yuanta Securities.

Nexon shares listed in Japan were down 5 percent as of 0437 GMT, while the broader Nikkei share average was 0.8 percent softer. Nexon affiliates Nexon GT and Nat Games both tumbled 19 percent after Reuters reported the postponement.

One of the sources said the bidding, scheduled for Wednesday, had been postponed by one week. The sources did not elaborate on the reasons for the delay and declined to be identified because the matter was confidential.

Billionaire Jungju Kim is selling a 98.64 percent stake held by himself and his wife in NXC, the holding company that owns 48 percent of Nexon, whose Dungeon Fighter game is a smash hit in South Korea and China.

Tencent is seen as the key to any deal since it owns the exclusive China licence for Dungeon Fighter.

Neople, the Nexon unit that developed the game, generated 1.24 trillion won ($1 billion) in revenue from Tencent in 2018, up 17 percent year on year, under a publishing deal which is effective till 2025, according to Neople’s public filings.